module Main (main) where

import IPS (Bytes, makeBytes)
import qualified IPS
import System.Environment (getArgs)
import System.Exit (exitFailure)
import System.IO (hPutBuf, withFile, IOMode(WriteMode))
import qualified Data.ByteString as ByteString
import qualified Data.Vector.Storable as Vector

main :: IO ()
main = do
  args <- getArgs
  case args of
    [inf, ipsf, outf] -> do
      buf <- readBytes inf
      ips <- either error id <$> IPS.parseFile ipsf
      writeBytes outf $ IPS.apply ips buf
    _ -> do
      putStrLn "usage: ips <in> <ips> <out>"
      exitFailure

readBytes :: FilePath -> IO Bytes
readBytes f = makeBytes <$> ByteString.readFile f

writeBytes :: FilePath -> Bytes -> IO ()
writeBytes f buf =
  withFile f WriteMode \h ->
  Vector.unsafeWith buf \ptr ->
  hPutBuf h ptr (Vector.length buf)